The 2018 San Luis Open Challenger Tour was a professional tennis tournament played on hard courts. It was the 25th edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in San Luis Potosí, Mexico between 27 March and 1 April 2018.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Italy | Paolo Lorenzi | 57 | 1 | |
 Austria | Gerald Melzer | 113 | 2 | |
| Yannick Hanfmann | 124 | 3 | ||
 Brazil | Thomaz Bellucci | 135 | 4 | |
 Dominican Republic | Víctor Estrella Burgos | 152 | 5 | |
| Evan King | 188 | 6 | ||
| Mitchell Krueger | 207 | 7 | ||
 Serbia | Peđa Krstin | 208 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
See main article: 2018 San Luis Open Challenger Tour – Singles.
Roberto Cid Subervi 6–3, 6–7(3–7), 6–4.See main article: 2018 San Luis Open Challenger Tour – Doubles.
Miguel Ángel Reyes-Varela def. 
Jay Clarke / Kevin Krawietz 6–1, 6–4.